This invention relates to suspended ceilings of the type wherein a plurality of spaced, elongated, individually suspended stringers cooperatively carry an array of ceiling panels. More particularly, it is directed to stabilizer bars for interconnecting adjacent stringers of a suspended ceiling, as well as to ceiling assemblies including such stabilizer bars.
A typical conventional subceiling or suspended ceiling, as frequently provided in a room for aesthetic and/or other reasons, is constituted of an array of ceiling panels spaced some distance below the true structural ceiling of the room. Commonly, the panels of the subceiling are supported by a plurality of elongated carriers or stringers, which are elongated rigid members extending above the panels in spaced relation to each other and are themselves individually suspended from the structural ceiling by wires or rods located at intervals along their lengths. In an illustrative known form of suspended ceiling, to which detailed reference will be made herein for purposes of illustration, the ceiling panels are elongated metal or like resiliently deformable elements of upwardly opening C-shaped cross section, disposed in closely spaced parallel array with their downwardly-facing major surfaces in a common horizontal plane; the stringers supporting them are downwardly-opening horizontally elongated metal channel members each having a plurality of paired downwardly projecting seats on which the panels are snap-fitted. These stringers extend transversely of the panels, being individually suspended at a common elevation in widely spaced parallel relation to each other, so that each stringer supports a large number of the panels and each panel is supported by a plurality of the stringers.
The individual suspension of the stringers in the assembly just described ordinarily permits them some freedom of travel and angular movement. Accordingly, they are liable to become displaced out of strict parallelism with each other, during or even after installation of the panels. Such deviation of the stringers from parallelism hinders panel installation, and if it occurs when the panels are already in place, may cause distortion or dislodgment of panels or at least produce a corresponding and aesthetically undesirable nonparallel orientation of the panels. In addition, the ceiling assembly may undergo racking, which involves a more or less concerted angular (swinging) movement of the stringers again tending to result in misalignment, distortion and/or dislodgment of the panels. Further problems are encountered in assemblies wherein the stringers support structures such as lighting fixtures or heating, ventilating and air conditioning diffusers as well as the panels; if the load imposed on a stringer by one of these structures is eccentric, it can cause rotational movement of the stringer with like objectionable consequences.
Although movement of the stringers can be reduced by anchoring their opposite ends to the opposed walls of a room, it is often not feasible or not convenient to do so, and even if the stringer ends are thus anchored, their intermediate portions may not be adequately restrained from moving, especially when (as is frequently the case) the stringers are many feet in length. It has been proposed to provide cross members or spacer bars between adjacent stringers, to hold them in properly parallel relation to each other, but these previously proposed members or bars have, in general, not been arranged to prevent angular movement such as racking, and/or have been complex in structure or difficult to install.